1. Field of the Invention
This invention relates to a signal recording/reproducing method and apparatus for recording/reproducing signals on or from a signal record (recording, recordable or recorded) medium, a signal record medium having signals recorded thereon, and a signal transmitting/receiving method and apparatus for transmitting/receiving signal over a signal transmission medium.
2. Description of the Related Art
As a signal record medium for recording information signals, such as speech or various sorts of data, such signal record medium for optically recording the information signals, such as a compact disc for music or a CD-ROM employing the CD disc standard for data, is in widespread use. Recently, the standardization for a so-called digital video disc (DVD), as the next generation signal record medium, is also proceeding.
Meanwhile, the entire audio or video signals, for example, recorded on the signal record medium, such as CD, CD-ROM or DAD, may be read out by a reproducing apparatus and duplicated on another signal record medium capable of signal recording and reproduction, such as a hard disc, and the data thus copied on the hard disc may then be supplied to an encoder system for the CD, CD-ROM or DAD for formulating a new CD, CD-ROM or DAD, in order to prepare a CD, CD-ROM or a DAD having recorded thereon the same signals as those recorded on the original signal record medium.
If new signal recording media are produced in this manner one after another, it becomes impossible to discriminate whether the signals recorded on the signal record medium are original signals or copied signals. Of course, this problem is encountered not only in the disc-shaped record medium, such as the CD or CD-ROM, but also in a tape-shaped record medium or other signal recording media. It is therefore desirable that signals recorded on a given signal record medium can be identified to be original signals or copied signals. Although it has been practiced up to now to record in a pre-set area of the signal record medium the information specifying that original signals or copied signals have been recorded on the signal record medium, there lacks up to now a technique for identifying whether the signal is the original signal or the copied signal based on the signal itself.
It is therefore an object of the present invention to provide a signal record (recording, recordable or recorded) method and apparatus whereby the signals to be recorded on a signal record medium can be identified to be original signals or copied signals.
It is another object of the present invention to provide a signal reproducing method and apparatus whereby the signals already recorded on a signal record medium can be identified to be original signals or copied signals.
It is yet another object of the present invention to provide a signal transmitting method and apparatus whereby it is possible to identify the transmission hysteresis of transmitted signals.
With the signal recording method and apparatus and the signal transmission method and apparatus of the present invention, an identification signal relevant to the video signals and/or the audio signals is inserted as a portion of the video signals and/or the audio signals in a configuration of reducing the effect on the video signals and/or the audio signals, and the video signals is and/or the audio signals, into which has been inserted the identification signal, are recorded on a signal record medium or transmitted over a signal transmission medium.
With the signal reproducing method and apparatus and the signal receiving method and apparatus of the present invention, the video signals and/or the audio signals reproduced from the signal record medium or transmitted over the signal transmission medium are received, and the identification signal, inserted as a portion of the video signals and/or the audio signals, is detected from the reproduced or received signals.
The signal record medium of the present invention has recorded thereon signals comprised of the video signals and/or the audio signals and an identification signal which is relevant to the video signals and/or the audio signals and which has been inserted as a portion of the video signals and/or the audio signals in a configuration of reducing the effect on the video signals and/or the audio signals.
According to the present invention, the meaningful identification signal is added to the video signals and/or the audio signals themselves in order to permit identification of these signals.
That is, according to the present invention, the identification signal relevant to the video signals and/or the audio signals is inserted as a portion of the video signals and/or the audio signals in a configuration of reducing the effect on the video signals and/or the audio signals and the video signals and/or the audio signals, to which has been inserted the identification signal as an ancillary signal, are recorded on a signal record medium or transmitted over a transmission medium. Thus, with the aid of the identification signal, it becomes possible to identify whether the signal recorded on a signal record medium is an original signal or a copied signal, while it also becomes possible to comprehend the hysteresis of the received signal. In addition, the identification signal, thus added to the video signals and/or the audio signals, is effective to prevent unauthorized copying.